Thrust control apparatus having inner and outer pintle nozzles controlled by common gear

Abstract

Provided is a thrust control apparatus having a plug area variable spike pintle nozzle, in which an aerospike-shaped pintle can be used in a pintle nozzle for precise thrust control. The thrust control apparatus includes a combustion chamber, a motor housing, and an outer pintle nozzle. The motor housing has a driving motor within the combustion chamber. The outer pintle nozzle is moved in a lateral direction by the driving motor.

What is claimed is: 
     
       1. A thrust control apparatus comprising:
 a combustion chamber containing a solid propellant; 
 a motor housing having a driving motor within the combustion chamber; 
 an outer pintle nozzle movable in a lateral direction by the driving motor; 
 an inner pintle nozzle disposed at a predetermined radial distance from the outer pintle nozzle; and 
 a gear connected to a central shaft of the driving motor to make the driving motor in rotational engagement with the outer pintle nozzle and the inner pintle nozzle, 
 wherein different threads are provided on outer and inner surfaces of the gear such that the outer pintle nozzle and the inner pintle nozzle have different movement speeds, and 
 wherein the outer pintle nozzles and the inner pintle nozzles have different gear ratios such that a plug area varies depending on the positions of the outer pintle nozzles and the inner pintle nozzles. 
 
     
     
       2. The thrust control apparatus according to  claim 1 , wherein propellant is located in an inner portion of the combustion chamber. 
     
     
       3. The thrust control apparatus according to  claim 1 , wherein the outer pintle nozzle comprises an aerospike pintle nozzle. 
     
     
       4. The thrust control apparatus according to  claim 1 , wherein an air gap is provided in a space between the outer pintle nozzle and the inner pintle nozzle to provide a heat insulation effect. 
     
     
       5. The thrust control apparatus according to  claim 1 , wherein a first thread of the different threads is provided on the outer surface of the gear, a second thread of the different threads is provided on the inner surface of the gear, and the size of the first thread is smaller than the size of the second thread. 
     
     
       6. The thrust control apparatus according to  claim 5 , wherein the second thread extends to an inner portion of the inner surface of the gear, and the first thread is only provided on a portion of the outer surface of the gear. 
     
     
       7. The thrust control apparatus according to  claim 5 , wherein a third thread is provided on an inner surface of the outer pintle nozzle to be meshed with the first thread. 
     
     
       8. The thrust control apparatus according to  claim 7 , wherein the third thread is provided on a portion of the inner surface of the outer pintle nozzle to limit a distance to which the outer pintle nozzle is movable. 
     
     
       9. The thrust control apparatus according to  claim 7 , wherein a fourth thread is provided on an outer surface of the inner pintle nozzle to be meshed with the second thread. 
     
     
       10. The thrust control apparatus according to  claim 9 , wherein the fourth thread is provided on a portion of the outer surface of the inner pintle nozzle to limit a distance to which the inner pintle nozzle is movable. 
     
     
       11. The thrust control apparatus according to  claim 9 , wherein the size of the fourth thread is greater than the size of the third thread so that a movement speed of one of the outer pintle nozzles is different from a movement speed of one of the inner pintle nozzles.